gdb/go-exp.y

   1 /* YACC parser for Go expressions, for GDB.
   2
   3    Copyright (C) 2012-2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file is derived from c-exp.y, p-exp.y.  */
  21
  22 /* Parse a Go expression from text in a string,
  23    and return the result as a struct expression pointer.
  24    That structure contains arithmetic operations in reverse polish,
  25    with constants represented by operations that are followed by special data.
  26    See expression.h for the details of the format.
  27    What is important here is that it can be built up sequentially
  28    during the process of parsing; the lower levels of the tree always
  29    come first in the result.
  30
  31    Note that malloc's and realloc's in this file are transformed to
  32    xmalloc and xrealloc respectively by the same sed command in the
  33    makefile that remaps any other malloc/realloc inserted by the parser
  34    generator.  Doing this with #defines and trying to control the interaction
  35    with include files (<malloc.h> and <stdlib.h> for example) just became
  36    too messy, particularly when such includes can be inserted at random
  37    times by the parser generator.  */
  38
  39 /* Known bugs or limitations:
  40
  41    - Unicode
  42    - &^
  43    - '_' (blank identifier)
  44    - automatic deref of pointers
  45    - method expressions
  46    - interfaces, channels, etc.
  47
  48    And lots of other things.
  49    I'm sure there's some cleanup to do.
  50 */
  51
  52 %{
  53
  54 #include "defs.h"
  55 #include <ctype.h>
  56 #include "expression.h"
  57 #include "value.h"
  58 #include "parser-defs.h"
  59 #include "language.h"
  60 #include "c-lang.h"
  61 #include "go-lang.h"
  62 #include "bfd.h" /* Required by objfiles.h.  */
  63 #include "symfile.h" /* Required by objfiles.h.  */
  64 #include "objfiles.h" /* For have_full_symbols and have_partial_symbols */
  65 #include "charset.h"
  66 #include "block.h"
  67
  68 #define parse_type(ps) builtin_type (parse_gdbarch (ps))
  69
  70 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  71    as well as gratuitiously global symbol names, so we can have multiple
  72    yacc generated parsers in gdb.  Note that these are only the variables
  73    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  74    additional global names that conflict at link time, then those parser
  75    generators need to be fixed instead of adding those names to this list.  */
  76
  77 #define yymaxdepth go_maxdepth
  78 #define yyparse go_parse_internal
  79 #define yylex   go_lex
  80 #define yyerror go_error
  81 #define yylval  go_lval
  82 #define yychar  go_char
  83 #define yydebug go_debug
  84 #define yypact  go_pact
  85 #define yyr1    go_r1
  86 #define yyr2    go_r2
  87 #define yydef   go_def
  88 #define yychk   go_chk
  89 #define yypgo   go_pgo
  90 #define yyact   go_act
  91 #define yyexca  go_exca
  92 #define yyerrflag go_errflag
  93 #define yynerrs go_nerrs
  94 #define yyps    go_ps
  95 #define yypv    go_pv
  96 #define yys     go_s
  97 #define yy_yys  go_yys
  98 #define yystate go_state
  99 #define yytmp   go_tmp
 100 #define yyv     go_v
 101 #define yy_yyv  go_yyv
 102 #define yyval   go_val
 103 #define yylloc  go_lloc
 104 #define yyreds  go_reds         /* With YYDEBUG defined */
 105 #define yytoks  go_toks         /* With YYDEBUG defined */
 106 #define yyname  go_name         /* With YYDEBUG defined */
 107 #define yyrule  go_rule         /* With YYDEBUG defined */
 108 #define yylhs   go_yylhs
 109 #define yylen   go_yylen
 110 #define yydefred go_yydefred
 111 #define yydgoto go_yydgoto
 112 #define yysindex go_yysindex
 113 #define yyrindex go_yyrindex
 114 #define yygindex go_yygindex
 115 #define yytable  go_yytable
 116 #define yycheck  go_yycheck
 117
 118 #ifndef YYDEBUG
 119 #define YYDEBUG 1               /* Default to yydebug support */
 120 #endif
 121
 122 #define YYFPRINTF parser_fprintf
 123
 124 /* The state of the parser, used internally when we are parsing the
 125    expression.  */
 126
 127 static struct parser_state *pstate = NULL;
 128
 129 int yyparse (void);
 130
 131 static int yylex (void);
 132
 133 void yyerror (char *);
 134
 135 %}
 136
 137 /* Although the yacc "value" of an expression is not used,
 138    since the result is stored in the structure being created,
 139    other node types do have values.  */
 140
 141 %union
 142   {
 143     LONGEST lval;
 144     struct {
 145       LONGEST val;
 146       struct type *type;
 147     } typed_val_int;
 148     struct {
 149       DOUBLEST dval;
 150       struct type *type;
 151     } typed_val_float;
 152     struct stoken sval;
 153     struct symtoken ssym;
 154     struct type *tval;
 155     struct typed_stoken tsval;
 156     struct ttype tsym;
 157     int voidval;
 158     enum exp_opcode opcode;
 159     struct internalvar *ivar;
 160     struct stoken_vector svec;
 161   }
 162
 163 %{
 164 /* YYSTYPE gets defined by %union.  */
 165 static int parse_number (struct parser_state *,
 166                          const char *, int, int, YYSTYPE *);
 167 static int parse_go_float (struct gdbarch *gdbarch, const char *p, int len,
 168                            DOUBLEST *d, struct type **t);
 169 %}
 170
 171 %type <voidval> exp exp1 type_exp start variable lcurly
 172 %type <lval> rcurly
 173 %type <tval> type
 174
 175 %token <typed_val_int> INT
 176 %token <typed_val_float> FLOAT
 177
 178 /* Both NAME and TYPENAME tokens represent symbols in the input,
 179    and both convey their data as strings.
 180    But a TYPENAME is a string that happens to be defined as a type
 181    or builtin type name (such as int or char)
 182    and a NAME is any other symbol.
 183    Contexts where this distinction is not important can use the
 184    nonterminal "name", which matches either NAME or TYPENAME.  */
 185
 186 %token <tsval> RAW_STRING
 187 %token <tsval> STRING
 188 %token <tsval> CHAR
 189 %token <ssym> NAME
 190 %token <tsym> TYPENAME /* Not TYPE_NAME cus already taken.  */
 191 %token <voidval> COMPLETE
 192 /*%type <sval> name*/
 193 %type <svec> string_exp
 194 %type <ssym> name_not_typename
 195
 196 /* A NAME_OR_INT is a symbol which is not known in the symbol table,
 197    but which would parse as a valid number in the current input radix.
 198    E.g. "c" when input_radix==16.  Depending on the parse, it will be
 199    turned into a name or into a number.  */
 200 %token <ssym> NAME_OR_INT
 201
 202 %token <lval> TRUE_KEYWORD FALSE_KEYWORD
 203 %token STRUCT_KEYWORD INTERFACE_KEYWORD TYPE_KEYWORD CHAN_KEYWORD
 204 %token SIZEOF_KEYWORD
 205 %token LEN_KEYWORD CAP_KEYWORD
 206 %token NEW_KEYWORD
 207 %token IOTA_KEYWORD NIL_KEYWORD
 208 %token CONST_KEYWORD
 209 %token DOTDOTDOT
 210 %token ENTRY
 211 %token ERROR
 212
 213 /* Special type cases.  */
 214 %token BYTE_KEYWORD /* An alias of uint8.  */
 215
 216 %token <sval> DOLLAR_VARIABLE
 217
 218 %token <opcode> ASSIGN_MODIFY
 219
 220 %left ','
 221 %left ABOVE_COMMA
 222 %right '=' ASSIGN_MODIFY
 223 %right '?'
 224 %left OROR
 225 %left ANDAND
 226 %left '|'
 227 %left '^'
 228 %left '&'
 229 %left ANDNOT
 230 %left EQUAL NOTEQUAL
 231 %left '<' '>' LEQ GEQ
 232 %left LSH RSH
 233 %left '@'
 234 %left '+' '-'
 235 %left '*' '/' '%'
 236 %right UNARY INCREMENT DECREMENT
 237 %right LEFT_ARROW '.' '[' '('
 238
 239 \f
 240 %%
 241
 242 start   :       exp1
 243         |       type_exp
 244         ;
 245
 246 type_exp:       type
 247                         { write_exp_elt_opcode (pstate, OP_TYPE);
 248                           write_exp_elt_type (pstate, $1);
 249                           write_exp_elt_opcode (pstate, OP_TYPE); }
 250         ;
 251
 252 /* Expressions, including the comma operator.  */
 253 exp1    :       exp
 254         |       exp1 ',' exp
 255                         { write_exp_elt_opcode (pstate, BINOP_COMMA); }
 256         ;
 257
 258 /* Expressions, not including the comma operator.  */
 259 exp     :       '*' exp    %prec UNARY
 260                         { write_exp_elt_opcode (pstate, UNOP_IND); }
 261         ;
 262
 263 exp     :       '&' exp    %prec UNARY
 264                         { write_exp_elt_opcode (pstate, UNOP_ADDR); }
 265         ;
 266
 267 exp     :       '-' exp    %prec UNARY
 268                         { write_exp_elt_opcode (pstate, UNOP_NEG); }
 269         ;
 270
 271 exp     :       '+' exp    %prec UNARY
 272                         { write_exp_elt_opcode (pstate, UNOP_PLUS); }
 273         ;
 274
 275 exp     :       '!' exp    %prec UNARY
 276                         { write_exp_elt_opcode (pstate, UNOP_LOGICAL_NOT); }
 277         ;
 278
 279 exp     :       '^' exp    %prec UNARY
 280                         { write_exp_elt_opcode (pstate, UNOP_COMPLEMENT); }
 281         ;
 282
 283 exp     :       exp INCREMENT    %prec UNARY
 284                         { write_exp_elt_opcode (pstate, UNOP_POSTINCREMENT); }
 285         ;
 286
 287 exp     :       exp DECREMENT    %prec UNARY
 288                         { write_exp_elt_opcode (pstate, UNOP_POSTDECREMENT); }
 289         ;
 290
 291 /* foo->bar is not in Go.  May want as a gdb extension.  Later.  */
 292
 293 exp     :       exp '.' name_not_typename
 294                         { write_exp_elt_opcode (pstate, STRUCTOP_STRUCT);
 295                           write_exp_string (pstate, $3.stoken);
 296                           write_exp_elt_opcode (pstate, STRUCTOP_STRUCT); }
 297         ;
 298
 299 exp     :       exp '.' name_not_typename COMPLETE
 300                         { mark_struct_expression (pstate);
 301                           write_exp_elt_opcode (pstate, STRUCTOP_STRUCT);
 302                           write_exp_string (pstate, $3.stoken);
 303                           write_exp_elt_opcode (pstate, STRUCTOP_STRUCT); }
 304         ;
 305
 306 exp     :       exp '.' COMPLETE
 307                         { struct stoken s;
 308                           mark_struct_expression (pstate);
 309                           write_exp_elt_opcode (pstate, STRUCTOP_STRUCT);
 310                           s.ptr = "";
 311                           s.length = 0;
 312                           write_exp_string (pstate, s);
 313                           write_exp_elt_opcode (pstate, STRUCTOP_STRUCT); }
 314         ;
 315
 316 exp     :       exp '[' exp1 ']'
 317                         { write_exp_elt_opcode (pstate, BINOP_SUBSCRIPT); }
 318         ;
 319
 320 exp     :       exp '('
 321                         /* This is to save the value of arglist_len
 322                            being accumulated by an outer function call.  */
 323                         { start_arglist (); }
 324                 arglist ')'     %prec LEFT_ARROW
 325                         { write_exp_elt_opcode (pstate, OP_FUNCALL);
 326                           write_exp_elt_longcst (pstate,
 327                                                  (LONGEST) end_arglist ());
 328                           write_exp_elt_opcode (pstate, OP_FUNCALL); }
 329         ;
 330
 331 lcurly  :       '{'
 332                         { start_arglist (); }
 333         ;
 334
 335 arglist :
 336         ;
 337
 338 arglist :       exp
 339                         { arglist_len = 1; }
 340         ;
 341
 342 arglist :       arglist ',' exp   %prec ABOVE_COMMA
 343                         { arglist_len++; }
 344         ;
 345
 346 rcurly  :       '}'
 347                         { $$ = end_arglist () - 1; }
 348         ;
 349
 350 exp     :       lcurly type rcurly exp  %prec UNARY
 351                         { write_exp_elt_opcode (pstate, UNOP_MEMVAL);
 352                           write_exp_elt_type (pstate, $2);
 353                           write_exp_elt_opcode (pstate, UNOP_MEMVAL); }
 354         ;
 355
 356 exp     :       type '(' exp ')'  %prec UNARY
 357                         { write_exp_elt_opcode (pstate, UNOP_CAST);
 358                           write_exp_elt_type (pstate, $1);
 359                           write_exp_elt_opcode (pstate, UNOP_CAST); }
 360         ;
 361
 362 exp     :       '(' exp1 ')'
 363                         { }
 364         ;
 365
 366 /* Binary operators in order of decreasing precedence.  */
 367
 368 exp     :       exp '@' exp
 369                         { write_exp_elt_opcode (pstate, BINOP_REPEAT); }
 370         ;
 371
 372 exp     :       exp '*' exp
 373                         { write_exp_elt_opcode (pstate, BINOP_MUL); }
 374         ;
 375
 376 exp     :       exp '/' exp
 377                         { write_exp_elt_opcode (pstate, BINOP_DIV); }
 378         ;
 379
 380 exp     :       exp '%' exp
 381                         { write_exp_elt_opcode (pstate, BINOP_REM); }
 382         ;
 383
 384 exp     :       exp '+' exp
 385                         { write_exp_elt_opcode (pstate, BINOP_ADD); }
 386         ;
 387
 388 exp     :       exp '-' exp
 389                         { write_exp_elt_opcode (pstate, BINOP_SUB); }
 390         ;
 391
 392 exp     :       exp LSH exp
 393                         { write_exp_elt_opcode (pstate, BINOP_LSH); }
 394         ;
 395
 396 exp     :       exp RSH exp
 397                         { write_exp_elt_opcode (pstate, BINOP_RSH); }
 398         ;
 399
 400 exp     :       exp EQUAL exp
 401                         { write_exp_elt_opcode (pstate, BINOP_EQUAL); }
 402         ;
 403
 404 exp     :       exp NOTEQUAL exp
 405                         { write_exp_elt_opcode (pstate, BINOP_NOTEQUAL); }
 406         ;
 407
 408 exp     :       exp LEQ exp
 409                         { write_exp_elt_opcode (pstate, BINOP_LEQ); }
 410         ;
 411
 412 exp     :       exp GEQ exp
 413                         { write_exp_elt_opcode (pstate, BINOP_GEQ); }
 414         ;
 415
 416 exp     :       exp '<' exp
 417                         { write_exp_elt_opcode (pstate, BINOP_LESS); }
 418         ;
 419
 420 exp     :       exp '>' exp
 421                         { write_exp_elt_opcode (pstate, BINOP_GTR); }
 422         ;
 423
 424 exp     :       exp '&' exp
 425                         { write_exp_elt_opcode (pstate, BINOP_BITWISE_AND); }
 426         ;
 427
 428 exp     :       exp '^' exp
 429                         { write_exp_elt_opcode (pstate, BINOP_BITWISE_XOR); }
 430         ;
 431
 432 exp     :       exp '|' exp
 433                         { write_exp_elt_opcode (pstate, BINOP_BITWISE_IOR); }
 434         ;
 435
 436 exp     :       exp ANDAND exp
 437                         { write_exp_elt_opcode (pstate, BINOP_LOGICAL_AND); }
 438         ;
 439
 440 exp     :       exp OROR exp
 441                         { write_exp_elt_opcode (pstate, BINOP_LOGICAL_OR); }
 442         ;
 443
 444 exp     :       exp '?' exp ':' exp     %prec '?'
 445                         { write_exp_elt_opcode (pstate, TERNOP_COND); }
 446         ;
 447
 448 exp     :       exp '=' exp
 449                         { write_exp_elt_opcode (pstate, BINOP_ASSIGN); }
 450         ;
 451
 452 exp     :       exp ASSIGN_MODIFY exp
 453                         { write_exp_elt_opcode (pstate, BINOP_ASSIGN_MODIFY);
 454                           write_exp_elt_opcode (pstate, $2);
 455                           write_exp_elt_opcode (pstate, BINOP_ASSIGN_MODIFY); }
 456         ;
 457
 458 exp     :       INT
 459                         { write_exp_elt_opcode (pstate, OP_LONG);
 460                           write_exp_elt_type (pstate, $1.type);
 461                           write_exp_elt_longcst (pstate, (LONGEST)($1.val));
 462                           write_exp_elt_opcode (pstate, OP_LONG); }
 463         ;
 464
 465 exp     :       CHAR
 466                         {
 467                           struct stoken_vector vec;
 468                           vec.len = 1;
 469                           vec.tokens = &$1;
 470                           write_exp_string_vector (pstate, $1.type, &vec);
 471                         }
 472         ;
 473
 474 exp     :       NAME_OR_INT
 475                         { YYSTYPE val;
 476                           parse_number (pstate, $1.stoken.ptr,
 477                                         $1.stoken.length, 0, &val);
 478                           write_exp_elt_opcode (pstate, OP_LONG);
 479                           write_exp_elt_type (pstate, val.typed_val_int.type);
 480                           write_exp_elt_longcst (pstate, (LONGEST)
 481                                                  val.typed_val_int.val);
 482                           write_exp_elt_opcode (pstate, OP_LONG);
 483                         }
 484         ;
 485
 486
 487 exp     :       FLOAT
 488                         { write_exp_elt_opcode (pstate, OP_DOUBLE);
 489                           write_exp_elt_type (pstate, $1.type);
 490                           write_exp_elt_dblcst (pstate, $1.dval);
 491                           write_exp_elt_opcode (pstate, OP_DOUBLE); }
 492         ;
 493
 494 exp     :       variable
 495         ;
 496
 497 exp     :       DOLLAR_VARIABLE
 498                         {
 499                           write_dollar_variable (pstate, $1);
 500                         }
 501         ;
 502
 503 exp     :       SIZEOF_KEYWORD '(' type ')'  %prec UNARY
 504                         {
 505                           /* TODO(dje): Go objects in structs.  */
 506                           write_exp_elt_opcode (pstate, OP_LONG);
 507                           /* TODO(dje): What's the right type here?  */
 508                           write_exp_elt_type
 509                             (pstate,
 510                              parse_type (pstate)->builtin_unsigned_int);
 511                           CHECK_TYPEDEF ($3);
 512                           write_exp_elt_longcst (pstate,
 513                                                  (LONGEST) TYPE_LENGTH ($3));
 514                           write_exp_elt_opcode (pstate, OP_LONG);
 515                         }
 516         ;
 517
 518 exp     :       SIZEOF_KEYWORD  '(' exp ')'  %prec UNARY
 519                         {
 520                           /* TODO(dje): Go objects in structs.  */
 521                           write_exp_elt_opcode (pstate, UNOP_SIZEOF);
 522                         }
 523
 524 string_exp:
 525                 STRING
 526                         {
 527                           /* We copy the string here, and not in the
 528                              lexer, to guarantee that we do not leak a
 529                              string.  */
 530                           /* Note that we NUL-terminate here, but just
 531                              for convenience.  */
 532                           struct typed_stoken *vec = XNEW (struct typed_stoken);
 533                           $$.len = 1;
 534                           $$.tokens = vec;
 535
 536                           vec->type = $1.type;
 537                           vec->length = $1.length;
 538                           vec->ptr = malloc ($1.length + 1);
 539                           memcpy (vec->ptr, $1.ptr, $1.length + 1);
 540                         }
 541
 542         |       string_exp '+' STRING
 543                         {
 544                           /* Note that we NUL-terminate here, but just
 545                              for convenience.  */
 546                           char *p;
 547                           ++$$.len;
 548                           $$.tokens = realloc ($$.tokens,
 549                                                $$.len * sizeof (struct typed_stoken));
 550
 551                           p = malloc ($3.length + 1);
 552                           memcpy (p, $3.ptr, $3.length + 1);
 553
 554                           $$.tokens[$$.len - 1].type = $3.type;
 555                           $$.tokens[$$.len - 1].length = $3.length;
 556                           $$.tokens[$$.len - 1].ptr = p;
 557                         }
 558         ;
 559
 560 exp     :       string_exp  %prec ABOVE_COMMA
 561                         {
 562                           int i;
 563
 564                           write_exp_string_vector (pstate, 0 /*always utf8*/,
 565                                                    &$1);
 566                           for (i = 0; i < $1.len; ++i)
 567                             free ($1.tokens[i].ptr);
 568                           free ($1.tokens);
 569                         }
 570         ;
 571
 572 exp     :       TRUE_KEYWORD
 573                         { write_exp_elt_opcode (pstate, OP_BOOL);
 574                           write_exp_elt_longcst (pstate, (LONGEST) $1);
 575                           write_exp_elt_opcode (pstate, OP_BOOL); }
 576         ;
 577
 578 exp     :       FALSE_KEYWORD
 579                         { write_exp_elt_opcode (pstate, OP_BOOL);
 580                           write_exp_elt_longcst (pstate, (LONGEST) $1);
 581                           write_exp_elt_opcode (pstate, OP_BOOL); }
 582         ;
 583
 584 variable:       name_not_typename ENTRY
 585                         { struct symbol *sym = $1.sym;
 586
 587                           if (sym == NULL
 588                               || !SYMBOL_IS_ARGUMENT (sym)
 589                               || !symbol_read_needs_frame (sym))
 590                             error (_("@entry can be used only for function "
 591                                      "parameters, not for \"%s\""),
 592                                    copy_name ($1.stoken));
 593
 594                           write_exp_elt_opcode (pstate, OP_VAR_ENTRY_VALUE);
 595                           write_exp_elt_sym (pstate, sym);
 596                           write_exp_elt_opcode (pstate, OP_VAR_ENTRY_VALUE);
 597                         }
 598         ;
 599
 600 variable:       name_not_typename
 601                         { struct symbol *sym = $1.sym;
 602
 603                           if (sym)
 604                             {
 605                               if (symbol_read_needs_frame (sym))
 606                                 {
 607                                   if (innermost_block == 0
 608                                       || contained_in (block_found,
 609                                                        innermost_block))
 610                                     innermost_block = block_found;
 611                                 }
 612
 613                               write_exp_elt_opcode (pstate, OP_VAR_VALUE);
 614                               /* We want to use the selected frame, not
 615                                  another more inner frame which happens to
 616                                  be in the same block.  */
 617                               write_exp_elt_block (pstate, NULL);
 618                               write_exp_elt_sym (pstate, sym);
 619                               write_exp_elt_opcode (pstate, OP_VAR_VALUE);
 620                             }
 621                           else if ($1.is_a_field_of_this)
 622                             {
 623                               /* TODO(dje): Can we get here?
 624                                  E.g., via a mix of c++ and go?  */
 625                               gdb_assert_not_reached ("go with `this' field");
 626                             }
 627                           else
 628                             {
 629                               struct bound_minimal_symbol msymbol;
 630                               char *arg = copy_name ($1.stoken);
 631
 632                               msymbol =
 633                                 lookup_bound_minimal_symbol (arg);
 634                               if (msymbol.minsym != NULL)
 635                                 write_exp_msymbol (pstate, msymbol);
 636                               else if (!have_full_symbols ()
 637                                        && !have_partial_symbols ())
 638                                 error (_("No symbol table is loaded.  "
 639                                        "Use the \"file\" command."));
 640                               else
 641                                 error (_("No symbol \"%s\" in current context."),
 642                                        copy_name ($1.stoken));
 643                             }
 644                         }
 645         ;
 646
 647 /* TODO
 648 method_exp: PACKAGENAME '.' name '.' name
 649                         {
 650                         }
 651         ;
 652 */
 653
 654 type  /* Implements (approximately): [*] type-specifier */
 655         :       '*' type
 656                         { $$ = lookup_pointer_type ($2); }
 657         |       TYPENAME
 658                         { $$ = $1.type; }
 659 /*
 660         |       STRUCT_KEYWORD name
 661                         { $$ = lookup_struct (copy_name ($2),
 662                                               expression_context_block); }
 663 */
 664         |       BYTE_KEYWORD
 665                         { $$ = builtin_go_type (parse_gdbarch (pstate))
 666                             ->builtin_uint8; }
 667         ;
 668
 669 /* TODO
 670 name    :       NAME { $$ = $1.stoken; }
 671         |       TYPENAME { $$ = $1.stoken; }
 672         |       NAME_OR_INT  { $$ = $1.stoken; }
 673         ;
 674 */
 675
 676 name_not_typename
 677         :       NAME
 678 /* These would be useful if name_not_typename was useful, but it is just
 679    a fake for "variable", so these cause reduce/reduce conflicts because
 680    the parser can't tell whether NAME_OR_INT is a name_not_typename (=variable,
 681    =exp) or just an exp.  If name_not_typename was ever used in an lvalue
 682    context where only a name could occur, this might be useful.
 683         |       NAME_OR_INT
 684 */
 685         ;
 686
 687 %%
 688
 689 /* Wrapper on parse_c_float to get the type right for Go.  */
 690
 691 static int
 692 parse_go_float (struct gdbarch *gdbarch, const char *p, int len,
 693                 DOUBLEST *d, struct type **t)
 694 {
 695   int result = parse_c_float (gdbarch, p, len, d, t);
 696   const struct builtin_type *builtin_types = builtin_type (gdbarch);
 697   const struct builtin_go_type *builtin_go_types = builtin_go_type (gdbarch);
 698
 699   if (*t == builtin_types->builtin_float)
 700     *t = builtin_go_types->builtin_float32;
 701   else if (*t == builtin_types->builtin_double)
 702     *t = builtin_go_types->builtin_float64;
 703
 704   return result;
 705 }
 706
 707 /* Take care of parsing a number (anything that starts with a digit).
 708    Set yylval and return the token type; update lexptr.
 709    LEN is the number of characters in it.  */
 710
 711 /* FIXME: Needs some error checking for the float case.  */
 712 /* FIXME(dje): IWBN to use c-exp.y's parse_number if we could.
 713    That will require moving the guts into a function that we both call
 714    as our YYSTYPE is different than c-exp.y's  */
 715
 716 static int
 717 parse_number (struct parser_state *par_state,
 718               const char *p, int len, int parsed_float, YYSTYPE *putithere)
 719 {
 720   /* FIXME: Shouldn't these be unsigned?  We don't deal with negative values
 721      here, and we do kind of silly things like cast to unsigned.  */
 722   LONGEST n = 0;
 723   LONGEST prevn = 0;
 724   ULONGEST un;
 725
 726   int i = 0;
 727   int c;
 728   int base = input_radix;
 729   int unsigned_p = 0;
 730
 731   /* Number of "L" suffixes encountered.  */
 732   int long_p = 0;
 733
 734   /* We have found a "L" or "U" suffix.  */
 735   int found_suffix = 0;
 736
 737   ULONGEST high_bit;
 738   struct type *signed_type;
 739   struct type *unsigned_type;
 740
 741   if (parsed_float)
 742     {
 743       if (! parse_go_float (parse_gdbarch (par_state), p, len,
 744                             &putithere->typed_val_float.dval,
 745                             &putithere->typed_val_float.type))
 746         return ERROR;
 747       return FLOAT;
 748     }
 749
 750   /* Handle base-switching prefixes 0x, 0t, 0d, 0.  */
 751   if (p[0] == '0')
 752     switch (p[1])
 753       {
 754       case 'x':
 755       case 'X':
 756         if (len >= 3)
 757           {
 758             p += 2;
 759             base = 16;
 760             len -= 2;
 761           }
 762         break;
 763
 764       case 'b':
 765       case 'B':
 766         if (len >= 3)
 767           {
 768             p += 2;
 769             base = 2;
 770             len -= 2;
 771           }
 772         break;
 773
 774       case 't':
 775       case 'T':
 776       case 'd':
 777       case 'D':
 778         if (len >= 3)
 779           {
 780             p += 2;
 781             base = 10;
 782             len -= 2;
 783           }
 784         break;
 785
 786       default:
 787         base = 8;
 788         break;
 789       }
 790
 791   while (len-- > 0)
 792     {
 793       c = *p++;
 794       if (c >= 'A' && c <= 'Z')
 795         c += 'a' - 'A';
 796       if (c != 'l' && c != 'u')
 797         n *= base;
 798       if (c >= '0' && c <= '9')
 799         {
 800           if (found_suffix)
 801             return ERROR;
 802           n += i = c - '0';
 803         }
 804       else
 805         {
 806           if (base > 10 && c >= 'a' && c <= 'f')
 807             {
 808               if (found_suffix)
 809                 return ERROR;
 810               n += i = c - 'a' + 10;
 811             }
 812           else if (c == 'l')
 813             {
 814               ++long_p;
 815               found_suffix = 1;
 816             }
 817           else if (c == 'u')
 818             {
 819               unsigned_p = 1;
 820               found_suffix = 1;
 821             }
 822           else
 823             return ERROR;       /* Char not a digit */
 824         }
 825       if (i >= base)
 826         return ERROR;           /* Invalid digit in this base.  */
 827
 828       /* Portably test for overflow (only works for nonzero values, so make
 829          a second check for zero).  FIXME: Can't we just make n and prevn
 830          unsigned and avoid this?  */
 831       if (c != 'l' && c != 'u' && (prevn >= n) && n != 0)
 832         unsigned_p = 1;         /* Try something unsigned.  */
 833
 834       /* Portably test for unsigned overflow.
 835          FIXME: This check is wrong; for example it doesn't find overflow
 836          on 0x123456789 when LONGEST is 32 bits.  */
 837       if (c != 'l' && c != 'u' && n != 0)
 838         {
 839           if ((unsigned_p && (ULONGEST) prevn >= (ULONGEST) n))
 840             error (_("Numeric constant too large."));
 841         }
 842       prevn = n;
 843     }
 844
 845   /* An integer constant is an int, a long, or a long long.  An L
 846      suffix forces it to be long; an LL suffix forces it to be long
 847      long.  If not forced to a larger size, it gets the first type of
 848      the above that it fits in.  To figure out whether it fits, we
 849      shift it right and see whether anything remains.  Note that we
 850      can't shift sizeof (LONGEST) * HOST_CHAR_BIT bits or more in one
 851      operation, because many compilers will warn about such a shift
 852      (which always produces a zero result).  Sometimes gdbarch_int_bit
 853      or gdbarch_long_bit will be that big, sometimes not.  To deal with
 854      the case where it is we just always shift the value more than
 855      once, with fewer bits each time.  */
 856
 857   un = (ULONGEST)n >> 2;
 858   if (long_p == 0
 859       && (un >> (gdbarch_int_bit (parse_gdbarch (par_state)) - 2)) == 0)
 860     {
 861       high_bit
 862         = ((ULONGEST)1) << (gdbarch_int_bit (parse_gdbarch (par_state)) - 1);
 863
 864       /* A large decimal (not hex or octal) constant (between INT_MAX
 865          and UINT_MAX) is a long or unsigned long, according to ANSI,
 866          never an unsigned int, but this code treats it as unsigned
 867          int.  This probably should be fixed.  GCC gives a warning on
 868          such constants.  */
 869
 870       unsigned_type = parse_type (par_state)->builtin_unsigned_int;
 871       signed_type = parse_type (par_state)->builtin_int;
 872     }
 873   else if (long_p <= 1
 874            && (un >> (gdbarch_long_bit (parse_gdbarch (par_state)) - 2)) == 0)
 875     {
 876       high_bit
 877         = ((ULONGEST)1) << (gdbarch_long_bit (parse_gdbarch (par_state)) - 1);
 878       unsigned_type = parse_type (par_state)->builtin_unsigned_long;
 879       signed_type = parse_type (par_state)->builtin_long;
 880     }
 881   else
 882     {
 883       int shift;
 884       if (sizeof (ULONGEST) * HOST_CHAR_BIT
 885           < gdbarch_long_long_bit (parse_gdbarch (par_state)))
 886         /* A long long does not fit in a LONGEST.  */
 887         shift = (sizeof (ULONGEST) * HOST_CHAR_BIT - 1);
 888       else
 889         shift = (gdbarch_long_long_bit (parse_gdbarch (par_state)) - 1);
 890       high_bit = (ULONGEST) 1 << shift;
 891       unsigned_type = parse_type (par_state)->builtin_unsigned_long_long;
 892       signed_type = parse_type (par_state)->builtin_long_long;
 893     }
 894
 895    putithere->typed_val_int.val = n;
 896
 897    /* If the high bit of the worked out type is set then this number
 898       has to be unsigned.  */
 899
 900    if (unsigned_p || (n & high_bit))
 901      {
 902        putithere->typed_val_int.type = unsigned_type;
 903      }
 904    else
 905      {
 906        putithere->typed_val_int.type = signed_type;
 907      }
 908
 909    return INT;
 910 }
 911
 912 /* Temporary obstack used for holding strings.  */
 913 static struct obstack tempbuf;
 914 static int tempbuf_init;
 915
 916 /* Parse a string or character literal from TOKPTR.  The string or
 917    character may be wide or unicode.  *OUTPTR is set to just after the
 918    end of the literal in the input string.  The resulting token is
 919    stored in VALUE.  This returns a token value, either STRING or
 920    CHAR, depending on what was parsed.  *HOST_CHARS is set to the
 921    number of host characters in the literal.  */
 922
 923 static int
 924 parse_string_or_char (const char *tokptr, const char **outptr,
 925                       struct typed_stoken *value, int *host_chars)
 926 {
 927   int quote;
 928
 929   /* Build the gdb internal form of the input string in tempbuf.  Note
 930      that the buffer is null byte terminated *only* for the
 931      convenience of debugging gdb itself and printing the buffer
 932      contents when the buffer contains no embedded nulls.  Gdb does
 933      not depend upon the buffer being null byte terminated, it uses
 934      the length string instead.  This allows gdb to handle C strings
 935      (as well as strings in other languages) with embedded null
 936      bytes */
 937
 938   if (!tempbuf_init)
 939     tempbuf_init = 1;
 940   else
 941     obstack_free (&tempbuf, NULL);
 942   obstack_init (&tempbuf);
 943
 944   /* Skip the quote.  */
 945   quote = *tokptr;
 946   ++tokptr;
 947
 948   *host_chars = 0;
 949
 950   while (*tokptr)
 951     {
 952       char c = *tokptr;
 953       if (c == '\\')
 954         {
 955           ++tokptr;
 956           *host_chars += c_parse_escape (&tokptr, &tempbuf);
 957         }
 958       else if (c == quote)
 959         break;
 960       else
 961         {
 962           obstack_1grow (&tempbuf, c);
 963           ++tokptr;
 964           /* FIXME: this does the wrong thing with multi-byte host
 965              characters.  We could use mbrlen here, but that would
 966              make "set host-charset" a bit less useful.  */
 967           ++*host_chars;
 968         }
 969     }
 970
 971   if (*tokptr != quote)
 972     {
 973       if (quote == '"')
 974         error (_("Unterminated string in expression."));
 975       else
 976         error (_("Unmatched single quote."));
 977     }
 978   ++tokptr;
 979
 980   value->type = C_STRING | (quote == '\'' ? C_CHAR : 0); /*FIXME*/
 981   value->ptr = obstack_base (&tempbuf);
 982   value->length = obstack_object_size (&tempbuf);
 983
 984   *outptr = tokptr;
 985
 986   return quote == '\'' ? CHAR : STRING;
 987 }
 988
 989 struct token
 990 {
 991   char *oper;
 992   int token;
 993   enum exp_opcode opcode;
 994 };
 995
 996 static const struct token tokentab3[] =
 997   {
 998     {">>=", ASSIGN_MODIFY, BINOP_RSH},
 999     {"<<=", ASSIGN_MODIFY, BINOP_LSH},
1000     /*{"&^=", ASSIGN_MODIFY, BINOP_BITWISE_ANDNOT}, TODO */
1001     {"...", DOTDOTDOT, OP_NULL},
1002   };
1003
1004 static const struct token tokentab2[] =
1005   {
1006     {"+=", ASSIGN_MODIFY, BINOP_ADD},
1007     {"-=", ASSIGN_MODIFY, BINOP_SUB},
1008     {"*=", ASSIGN_MODIFY, BINOP_MUL},
1009     {"/=", ASSIGN_MODIFY, BINOP_DIV},
1010     {"%=", ASSIGN_MODIFY, BINOP_REM},
1011     {"|=", ASSIGN_MODIFY, BINOP_BITWISE_IOR},
1012     {"&=", ASSIGN_MODIFY, BINOP_BITWISE_AND},
1013     {"^=", ASSIGN_MODIFY, BINOP_BITWISE_XOR},
1014     {"++", INCREMENT, BINOP_END},
1015     {"--", DECREMENT, BINOP_END},
1016     /*{"->", RIGHT_ARROW, BINOP_END}, Doesn't exist in Go.  */
1017     {"<-", LEFT_ARROW, BINOP_END},
1018     {"&&", ANDAND, BINOP_END},
1019     {"||", OROR, BINOP_END},
1020     {"<<", LSH, BINOP_END},
1021     {">>", RSH, BINOP_END},
1022     {"==", EQUAL, BINOP_END},
1023     {"!=", NOTEQUAL, BINOP_END},
1024     {"<=", LEQ, BINOP_END},
1025     {">=", GEQ, BINOP_END},
1026     /*{"&^", ANDNOT, BINOP_END}, TODO */
1027   };
1028
1029 /* Identifier-like tokens.  */
1030 static const struct token ident_tokens[] =
1031   {
1032     {"true", TRUE_KEYWORD, OP_NULL},
1033     {"false", FALSE_KEYWORD, OP_NULL},
1034     {"nil", NIL_KEYWORD, OP_NULL},
1035     {"const", CONST_KEYWORD, OP_NULL},
1036     {"struct", STRUCT_KEYWORD, OP_NULL},
1037     {"type", TYPE_KEYWORD, OP_NULL},
1038     {"interface", INTERFACE_KEYWORD, OP_NULL},
1039     {"chan", CHAN_KEYWORD, OP_NULL},
1040     {"byte", BYTE_KEYWORD, OP_NULL}, /* An alias of uint8.  */
1041     {"len", LEN_KEYWORD, OP_NULL},
1042     {"cap", CAP_KEYWORD, OP_NULL},
1043     {"new", NEW_KEYWORD, OP_NULL},
1044     {"iota", IOTA_KEYWORD, OP_NULL},
1045   };
1046
1047 /* This is set if a NAME token appeared at the very end of the input
1048    string, with no whitespace separating the name from the EOF.  This
1049    is used only when parsing to do field name completion.  */
1050 static int saw_name_at_eof;
1051
1052 /* This is set if the previously-returned token was a structure
1053    operator -- either '.' or ARROW.  This is used only when parsing to
1054    do field name completion.  */
1055 static int last_was_structop;
1056
1057 /* Read one token, getting characters through lexptr.  */
1058
1059 static int
1060 lex_one_token (struct parser_state *par_state)
1061 {
1062   int c;
1063   int namelen;
1064   unsigned int i;
1065   const char *tokstart;
1066   int saw_structop = last_was_structop;
1067   char *copy;
1068
1069   last_was_structop = 0;
1070
1071  retry:
1072
1073   prev_lexptr = lexptr;
1074
1075   tokstart = lexptr;
1076   /* See if it is a special token of length 3.  */
1077   for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1078     if (strncmp (tokstart, tokentab3[i].oper, 3) == 0)
1079       {
1080         lexptr += 3;
1081         yylval.opcode = tokentab3[i].opcode;
1082         return tokentab3[i].token;
1083       }
1084
1085   /* See if it is a special token of length 2.  */
1086   for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1087     if (strncmp (tokstart, tokentab2[i].oper, 2) == 0)
1088       {
1089         lexptr += 2;
1090         yylval.opcode = tokentab2[i].opcode;
1091         /* NOTE: -> doesn't exist in Go, so we don't need to watch for
1092            setting last_was_structop here.  */
1093         return tokentab2[i].token;
1094       }
1095
1096   switch (c = *tokstart)
1097     {
1098     case 0:
1099       if (saw_name_at_eof)
1100         {
1101           saw_name_at_eof = 0;
1102           return COMPLETE;
1103         }
1104       else if (saw_structop)
1105         return COMPLETE;
1106       else
1107         return 0;
1108
1109     case ' ':
1110     case '\t':
1111     case '\n':
1112       lexptr++;
1113       goto retry;
1114
1115     case '[':
1116     case '(':
1117       paren_depth++;
1118       lexptr++;
1119       return c;
1120
1121     case ']':
1122     case ')':
1123       if (paren_depth == 0)
1124         return 0;
1125       paren_depth--;
1126       lexptr++;
1127       return c;
1128
1129     case ',':
1130       if (comma_terminates
1131           && paren_depth == 0)
1132         return 0;
1133       lexptr++;
1134       return c;
1135
1136     case '.':
1137       /* Might be a floating point number.  */
1138       if (lexptr[1] < '0' || lexptr[1] > '9')
1139         {
1140           if (parse_completion)
1141             last_was_structop = 1;
1142           goto symbol;          /* Nope, must be a symbol. */
1143         }
1144       /* FALL THRU into number case.  */
1145
1146     case '0':
1147     case '1':
1148     case '2':
1149     case '3':
1150     case '4':
1151     case '5':
1152     case '6':
1153     case '7':
1154     case '8':
1155     case '9':
1156       {
1157         /* It's a number.  */
1158         int got_dot = 0, got_e = 0, toktype;
1159         const char *p = tokstart;
1160         int hex = input_radix > 10;
1161
1162         if (c == '0' && (p[1] == 'x' || p[1] == 'X'))
1163           {
1164             p += 2;
1165             hex = 1;
1166           }
1167
1168         for (;; ++p)
1169           {
1170             /* This test includes !hex because 'e' is a valid hex digit
1171                and thus does not indicate a floating point number when
1172                the radix is hex.  */
1173             if (!hex && !got_e && (*p == 'e' || *p == 'E'))
1174               got_dot = got_e = 1;
1175             /* This test does not include !hex, because a '.' always indicates
1176                a decimal floating point number regardless of the radix.  */
1177             else if (!got_dot && *p == '.')
1178               got_dot = 1;
1179             else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
1180                      && (*p == '-' || *p == '+'))
1181               /* This is the sign of the exponent, not the end of the
1182                  number.  */
1183               continue;
1184             /* We will take any letters or digits.  parse_number will
1185                complain if past the radix, or if L or U are not final.  */
1186             else if ((*p < '0' || *p > '9')
1187                      && ((*p < 'a' || *p > 'z')
1188                                   && (*p < 'A' || *p > 'Z')))
1189               break;
1190           }
1191         toktype = parse_number (par_state, tokstart, p - tokstart,
1192                                 got_dot|got_e, &yylval);
1193         if (toktype == ERROR)
1194           {
1195             char *err_copy = (char *) alloca (p - tokstart + 1);
1196
1197             memcpy (err_copy, tokstart, p - tokstart);
1198             err_copy[p - tokstart] = 0;
1199             error (_("Invalid number \"%s\"."), err_copy);
1200           }
1201         lexptr = p;
1202         return toktype;
1203       }
1204
1205     case '@':
1206       {
1207         const char *p = &tokstart[1];
1208         size_t len = strlen ("entry");
1209
1210         while (isspace (*p))
1211           p++;
1212         if (strncmp (p, "entry", len) == 0 && !isalnum (p[len])
1213             && p[len] != '_')
1214           {
1215             lexptr = &p[len];
1216             return ENTRY;
1217           }
1218       }
1219       /* FALLTHRU */
1220     case '+':
1221     case '-':
1222     case '*':
1223     case '/':
1224     case '%':
1225     case '|':
1226     case '&':
1227     case '^':
1228     case '~':
1229     case '!':
1230     case '<':
1231     case '>':
1232     case '?':
1233     case ':':
1234     case '=':
1235     case '{':
1236     case '}':
1237     symbol:
1238       lexptr++;
1239       return c;
1240
1241     case '\'':
1242     case '"':
1243     case '`':
1244       {
1245         int host_len;
1246         int result = parse_string_or_char (tokstart, &lexptr, &yylval.tsval,
1247                                            &host_len);
1248         if (result == CHAR)
1249           {
1250             if (host_len == 0)
1251               error (_("Empty character constant."));
1252             else if (host_len > 2 && c == '\'')
1253               {
1254                 ++tokstart;
1255                 namelen = lexptr - tokstart - 1;
1256                 goto tryname;
1257               }
1258             else if (host_len > 1)
1259               error (_("Invalid character constant."));
1260           }
1261         return result;
1262       }
1263     }
1264
1265   if (!(c == '_' || c == '$'
1266         || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')))
1267     /* We must have come across a bad character (e.g. ';').  */
1268     error (_("Invalid character '%c' in expression."), c);
1269
1270   /* It's a name.  See how long it is.  */
1271   namelen = 0;
1272   for (c = tokstart[namelen];
1273        (c == '_' || c == '$' || (c >= '0' && c <= '9')
1274         || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));)
1275     {
1276       c = tokstart[++namelen];
1277     }
1278
1279   /* The token "if" terminates the expression and is NOT removed from
1280      the input stream.  It doesn't count if it appears in the
1281      expansion of a macro.  */
1282   if (namelen == 2
1283       && tokstart[0] == 'i'
1284       && tokstart[1] == 'f')
1285     {
1286       return 0;
1287     }
1288
1289   /* For the same reason (breakpoint conditions), "thread N"
1290      terminates the expression.  "thread" could be an identifier, but
1291      an identifier is never followed by a number without intervening
1292      punctuation.
1293      Handle abbreviations of these, similarly to
1294      breakpoint.c:find_condition_and_thread.
1295      TODO: Watch for "goroutine" here?  */
1296   if (namelen >= 1
1297       && strncmp (tokstart, "thread", namelen) == 0
1298       && (tokstart[namelen] == ' ' || tokstart[namelen] == '\t'))
1299     {
1300       const char *p = tokstart + namelen + 1;
1301
1302       while (*p == ' ' || *p == '\t')
1303         p++;
1304       if (*p >= '0' && *p <= '9')
1305         return 0;
1306     }
1307
1308   lexptr += namelen;
1309
1310   tryname:
1311
1312   yylval.sval.ptr = tokstart;
1313   yylval.sval.length = namelen;
1314
1315   /* Catch specific keywords.  */
1316   copy = copy_name (yylval.sval);
1317   for (i = 0; i < sizeof (ident_tokens) / sizeof (ident_tokens[0]); i++)
1318     if (strcmp (copy, ident_tokens[i].oper) == 0)
1319       {
1320         /* It is ok to always set this, even though we don't always
1321            strictly need to.  */
1322         yylval.opcode = ident_tokens[i].opcode;
1323         return ident_tokens[i].token;
1324       }
1325
1326   if (*tokstart == '$')
1327     return DOLLAR_VARIABLE;
1328
1329   if (parse_completion && *lexptr == '\0')
1330     saw_name_at_eof = 1;
1331   return NAME;
1332 }
1333
1334 /* An object of this type is pushed on a FIFO by the "outer" lexer.  */
1335 typedef struct
1336 {
1337   int token;
1338   YYSTYPE value;
1339 } token_and_value;
1340
1341 DEF_VEC_O (token_and_value);
1342
1343 /* A FIFO of tokens that have been read but not yet returned to the
1344    parser.  */
1345 static VEC (token_and_value) *token_fifo;
1346
1347 /* Non-zero if the lexer should return tokens from the FIFO.  */
1348 static int popping;
1349
1350 /* Temporary storage for yylex; this holds symbol names as they are
1351    built up.  */
1352 static struct obstack name_obstack;
1353
1354 /* Build "package.name" in name_obstack.
1355    For convenience of the caller, the name is NUL-terminated,
1356    but the NUL is not included in the recorded length.  */
1357
1358 static struct stoken
1359 build_packaged_name (const char *package, int package_len,
1360                      const char *name, int name_len)
1361 {
1362   struct stoken result;
1363
1364   obstack_free (&name_obstack, obstack_base (&name_obstack));
1365   obstack_grow (&name_obstack, package, package_len);
1366   obstack_grow_str (&name_obstack, ".");
1367   obstack_grow (&name_obstack, name, name_len);
1368   obstack_grow (&name_obstack, "", 1);
1369   result.ptr = obstack_base (&name_obstack);
1370   result.length = obstack_object_size (&name_obstack) - 1;
1371
1372   return result;
1373 }
1374
1375 /* Return non-zero if NAME is a package name.
1376    BLOCK is the scope in which to interpret NAME; this can be NULL
1377    to mean the global scope.  */
1378
1379 static int
1380 package_name_p (const char *name, const struct block *block)
1381 {
1382   struct symbol *sym;
1383   struct field_of_this_result is_a_field_of_this;
1384
1385   sym = lookup_symbol (name, block, STRUCT_DOMAIN, &is_a_field_of_this);
1386
1387   if (sym
1388       && SYMBOL_CLASS (sym) == LOC_TYPEDEF
1389       && TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_MODULE)
1390     return 1;
1391
1392   return 0;
1393 }
1394
1395 /* Classify a (potential) function in the "unsafe" package.
1396    We fold these into "keywords" to keep things simple, at least until
1397    something more complex is warranted.  */
1398
1399 static int
1400 classify_unsafe_function (struct stoken function_name)
1401 {
1402   char *copy = copy_name (function_name);
1403
1404   if (strcmp (copy, "Sizeof") == 0)
1405     {
1406       yylval.sval = function_name;
1407       return SIZEOF_KEYWORD;
1408     }
1409
1410   error (_("Unknown function in `unsafe' package: %s"), copy);
1411 }
1412
1413 /* Classify token(s) "name1.name2" where name1 is known to be a package.
1414    The contents of the token are in `yylval'.
1415    Updates yylval and returns the new token type.
1416
1417    The result is one of NAME, NAME_OR_INT, or TYPENAME.  */
1418
1419 static int
1420 classify_packaged_name (const struct block *block)
1421 {
1422   char *copy;
1423   struct symbol *sym;
1424   struct field_of_this_result is_a_field_of_this;
1425
1426   copy = copy_name (yylval.sval);
1427
1428   sym = lookup_symbol (copy, block, VAR_DOMAIN, &is_a_field_of_this);
1429
1430   if (sym)
1431     {
1432       yylval.ssym.sym = sym;
1433       yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
1434     }
1435
1436   return NAME;
1437 }
1438
1439 /* Classify a NAME token.
1440    The contents of the token are in `yylval'.
1441    Updates yylval and returns the new token type.
1442    BLOCK is the block in which lookups start; this can be NULL
1443    to mean the global scope.
1444
1445    The result is one of NAME, NAME_OR_INT, or TYPENAME.  */
1446
1447 static int
1448 classify_name (struct parser_state *par_state, const struct block *block)
1449 {
1450   struct type *type;
1451   struct symbol *sym;
1452   char *copy;
1453   struct field_of_this_result is_a_field_of_this;
1454
1455   copy = copy_name (yylval.sval);
1456
1457   /* Try primitive types first so they win over bad/weird debug info.  */
1458   type = language_lookup_primitive_type (parse_language (par_state),
1459                                          parse_gdbarch (par_state),
1460                                          copy);
1461   if (type != NULL)
1462     {
1463       /* NOTE: We take advantage of the fact that yylval coming in was a
1464          NAME, and that struct ttype is a compatible extension of struct
1465          stoken, so yylval.tsym.stoken is already filled in.  */
1466       yylval.tsym.type = type;
1467       return TYPENAME;
1468     }
1469
1470   /* TODO: What about other types?  */
1471
1472   sym = lookup_symbol (copy, block, VAR_DOMAIN, &is_a_field_of_this);
1473
1474   if (sym)
1475     {
1476       yylval.ssym.sym = sym;
1477       yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
1478       return NAME;
1479     }
1480
1481   /* If we didn't find a symbol, look again in the current package.
1482      This is to, e.g., make "p global_var" work without having to specify
1483      the package name.  We intentionally only looks for objects in the
1484      current package.  */
1485
1486   {
1487     char *current_package_name = go_block_package_name (block);
1488
1489     if (current_package_name != NULL)
1490       {
1491         struct stoken sval =
1492           build_packaged_name (current_package_name,
1493                                strlen (current_package_name),
1494                                copy, strlen (copy));
1495
1496         xfree (current_package_name);
1497         sym = lookup_symbol (sval.ptr, block, VAR_DOMAIN,
1498                              &is_a_field_of_this);
1499         if (sym)
1500           {
1501             yylval.ssym.stoken = sval;
1502             yylval.ssym.sym = sym;
1503             yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
1504             return NAME;
1505           }
1506       }
1507   }
1508
1509   /* Input names that aren't symbols but ARE valid hex numbers, when
1510      the input radix permits them, can be names or numbers depending
1511      on the parse.  Note we support radixes > 16 here.  */
1512   if ((copy[0] >= 'a' && copy[0] < 'a' + input_radix - 10)
1513       || (copy[0] >= 'A' && copy[0] < 'A' + input_radix - 10))
1514     {
1515       YYSTYPE newlval;  /* Its value is ignored.  */
1516       int hextype = parse_number (par_state, copy, yylval.sval.length,
1517                                   0, &newlval);
1518       if (hextype == INT)
1519         {
1520           yylval.ssym.sym = NULL;
1521           yylval.ssym.is_a_field_of_this = 0;
1522           return NAME_OR_INT;
1523         }
1524     }
1525
1526   yylval.ssym.sym = NULL;
1527   yylval.ssym.is_a_field_of_this = 0;
1528   return NAME;
1529 }
1530
1531 /* This is taken from c-exp.y mostly to get something working.
1532    The basic structure has been kept because we may yet need some of it.  */
1533
1534 static int
1535 yylex (void)
1536 {
1537   token_and_value current, next;
1538
1539   if (popping && !VEC_empty (token_and_value, token_fifo))
1540     {
1541       token_and_value tv = *VEC_index (token_and_value, token_fifo, 0);
1542       VEC_ordered_remove (token_and_value, token_fifo, 0);
1543       yylval = tv.value;
1544       /* There's no need to fall through to handle package.name
1545          as that can never happen here.  In theory.  */
1546       return tv.token;
1547     }
1548   popping = 0;
1549
1550   current.token = lex_one_token (pstate);
1551
1552   /* TODO: Need a way to force specifying name1 as a package.
1553      .name1.name2 ?  */
1554
1555   if (current.token != NAME)
1556     return current.token;
1557
1558   /* See if we have "name1 . name2".  */
1559
1560   current.value = yylval;
1561   next.token = lex_one_token (pstate);
1562   next.value = yylval;
1563
1564   if (next.token == '.')
1565     {
1566       token_and_value name2;
1567
1568       name2.token = lex_one_token (pstate);
1569       name2.value = yylval;
1570
1571       if (name2.token == NAME)
1572         {
1573           /* Ok, we have "name1 . name2".  */
1574           char *copy;
1575
1576           copy = copy_name (current.value.sval);
1577
1578           if (strcmp (copy, "unsafe") == 0)
1579             {
1580               popping = 1;
1581               return classify_unsafe_function (name2.value.sval);
1582             }
1583
1584           if (package_name_p (copy, expression_context_block))
1585             {
1586               popping = 1;
1587               yylval.sval = build_packaged_name (current.value.sval.ptr,
1588                                                  current.value.sval.length,
1589                                                  name2.value.sval.ptr,
1590                                                  name2.value.sval.length);
1591               return classify_packaged_name (expression_context_block);
1592             }
1593         }
1594
1595       VEC_safe_push (token_and_value, token_fifo, &next);
1596       VEC_safe_push (token_and_value, token_fifo, &name2);
1597     }
1598   else
1599     {
1600       VEC_safe_push (token_and_value, token_fifo, &next);
1601     }
1602
1603   /* If we arrive here we don't have a package-qualified name.  */
1604
1605   popping = 1;
1606   yylval = current.value;
1607   return classify_name (pstate, expression_context_block);
1608 }
1609
1610 int
1611 go_parse (struct parser_state *par_state)
1612 {
1613   int result;
1614   struct cleanup *back_to;
1615
1616   /* Setting up the parser state.  */
1617   gdb_assert (par_state != NULL);
1618   pstate = par_state;
1619
1620   back_to = make_cleanup (null_cleanup, NULL);
1621
1622   make_cleanup_restore_integer (&yydebug);
1623   make_cleanup_clear_parser_state (&pstate);
1624   yydebug = parser_debug;
1625
1626   /* Initialize some state used by the lexer.  */
1627   last_was_structop = 0;
1628   saw_name_at_eof = 0;
1629
1630   VEC_free (token_and_value, token_fifo);
1631   popping = 0;
1632   obstack_init (&name_obstack);
1633   make_cleanup_obstack_free (&name_obstack);
1634
1635   result = yyparse ();
1636   do_cleanups (back_to);
1637   return result;
1638 }
1639
1640 void
1641 yyerror (char *msg)
1642 {
1643   if (prev_lexptr)
1644     lexptr = prev_lexptr;
1645
1646   error (_("A %s in expression, near `%s'."), (msg ? msg : "error"), lexptr);
1647 }